No because you chose the wrong type of cancellation.
You can open an Unpaid Item Dispute four days (96 hours) after the purchase. I usually wait till Day 3 and send a polite note asking if the buyer needs any help with her Paypal. Not that I can help, but it opens communication if the buyer is just a slow payer.
If there is no satisfactory answer, the UID is opened on Day 4.
If she doesn't pay (and about half of these customers turn out to be just slow payers) I close the Dispute, get my fees back and she gets a Strike which makes it harder to bid in future.
What you did, I think, is open a Request for a Mutual Cancellation. Normally these are used when the buyer and seller mutually realize that this transaction is just not going to happen. The seller sends the Request, the buyer agrees, both are released, the seller gets his fees back, and both can leave feedback, usually friendly.
Now, if that was what you did, if the buyer ignores your Request it will close in your favour. Normally the fees would be deleted from your invoice, but in this case, I suspect they will show up as a credit on next month's fees.
In future, don't let deadbeats string you along. If they can't pay, they shouldn't be bidding, of course, but if they don't have the money, that's what credit cards are for. You get paid promptly and they can pay the card at their leisure. With interest.
Four days is plenty.
Our US sellers can open a UID in just 48 hours.
